Wietse Wind: I'm brainstorming here, if modern phones can't store NFC tags locally, we could integrate NFC tags to tangem cards which will enable NFC payments. I'll take a look at BLE, thanks.

Wo Jake: If using NFC based hardware + blockchain, without a phone interface, there's no way of telling if what you'll authorize is what you want to spend, and with blockchain finality that's a huge risk. Then if you loop in a phone again (e.g. multisign setup) it defeats the purpose to use NFC at all.

Wietse Wind: Ah my bad, I think it's not possible to use tangem cards for NFC payments because of the issue that you just disclosed, thank you.

I suppose we could only integrate NFC payments using modern phones that have NFC accessories.

Here's an example for NFC payments:

Situation 1: Bob buys groceries in a local super market.

Bob is paying 100 USD worth of groceries, he'll be using XUMM's NFC payment.

In a normal situation, Bob can safely pay using a debit card and a debit machine provided to him (pic), this is fine since payments are reversible, the system is also maintained by a centralized entity.

But if we use this method in the XRP Ledger which can validate a transaction in seconds, a malicious actor could take advantage of this model and siphon off large amounts of money without the victim knowing until they check their account.

So a phone with NFC accessories is needed to perform an NFC payment without any security risks. The phone must have an NFC scanner to obtain a payment request from the cashier (or a debit machine similar to the picture) to perform a fast and secure transaction.

Again, thank you very much for discovering this issue.

Wietse Wind:

After a few hours of research, some phones are equipped with two-way communication and they're expanding, this will allow phones to share data with each other using NFC. For example, users can touch their devices together to transfer data like contacts, wallet address and payment requests.

As Wietse Wind said in this comment:

"Other technologies to look at exist as well, think e.g. BLE (Bluetooth Low Energy)."

BLE and Bluetooth is a great protocol to use for payments but NFC is much better and is widely accepted;

Pairing two bluetooth devices can be an inconvenient to users:

-Turning on Bluetooth

-Make device discoverable

-Search for the corresponding user's device

-Enter passcode

One day, NFC will monopolize day-to-day payments in places like coffee shops, marketplaces and the train station.

Many retail shops like Target and Walgreens have integrated NFC-based pay terminals in place.

Wo Jake: For now we focus on QR exchanges of data only, as QRs are always available, also on older devices, and they require zero extra hardware on e.g. the Point of Sales.

It's the most universal way both on the side of the point of sales and the user facing side.

Also, no hardware upgrades/investments are required if something changes on the spec/security side of things. Preventing expensive hardware upgrades on the retail side is a big plus.

Wietse Wind: You're right, the need for additional hardware acts as a huge barrier for a majority of users but as R&D grows, more phones will be equipped with NFC accessories due to the growing demand and usage.

This proposal is good in theory but I suppose we can wait it out due to the lacking amount of phones equipped with NFC accessories.